* = $0200
VIA_DDRA = $FF03
VIA_ORA  = $FF01
LDA #$FF
STA VIA_DDRA
loop:
LDA #$00
STA VIA_ORA
JSR delay
LDA #$FF
STA VIA_ORA
JSR delay
JMP loop
delay:
DEY
BNE delay
DEX
BNE delay
RTS
